All wired up REV 1. This allows the redarc BCDC input from the solar panels and tow vehicle battery to be controlled by the redarc device, using the battery protection relay for undervoltage, SOC and DC converter/charger over voltage protection. Works good for me now.
There is a figure in the BP-100 'manual' I received (Rev08 27-03-2017) with the product with some words about second battery protect.
Here's an image of figure 5:
The caution is not sufficient to warn about possible fire when running current thru the BP100 in reverse.
In my case the current was limited to what the battery charger was rated at, 40A. Measured 36A thru BP100 in reverse direction. Limited current probably saved me from a fire. There was a small voltage drop across the BP100 when charging the battery from the charger (I was surprised about this but never figured out why).
Yes, I do consider myself lucky.
Do Not use a BP-100 to charge a battery with the Charger+ lead wired to the BP100 'out' stud and the Battery + lead wired to the BP100 'in' stud. This scheme runs current thru the BP100 in the reverse direction and can cause a fire.